South Africa's already slender grip on the Tri Nations title was just about torn decisively out of their grasp by the rampaging All Blacks in Melbourne yesterday.

The demolition job that Graham Henry's New Zealanders are doing in this year's tournament was underlined by this seven tries to three mauling of the Wallabies in their own backyard.

New Zealand are playing a game beyond the capacity or understanding of either South Africa or Australia. They will regain the Tri Nations trophy, not to mention the Bledisloe Cup if, as expected, they once again beat the Wallabies in Christchurch next Saturday.

Defeat would represent a disastrous ninth successive loss for Australia under coach Robbie Deans against their oldest foes. "Pressure?" Deans admitted. "Of course I feel the pressure. It's part of the territory. Your heart rate goes up but you go back to work.

"We have an opportunity next week in Christchurch so you keep going and try to find some solutions."

New Zealand played what their coach, Henry, called "scintillating rugby" to put the Wallabies to the sword. They built an impressive 32-14 half-time lead, the bonus point for four tries achieved within the opening 35 minutes.

A second yellow card, that meant red for Australian wing Drew Mitchell just three minutes after half-time, settled the match. "The sending off was obviously damaging; we suffered the consequences," Deans said. "Drew's action was costly and at that point the game at this level becomes a bit of a nonsense."

But in fairness to referee Craig Joubert, he had issued a general warning to both captains just six minutes before half-time. He was not happy with players preventing quickly taken free-kicks or penalties and warned them: "The next person that does it will be yellow carded."

Mitchell had already received a yellow card after 27 minutes (Owen Franks got one for NZ too) for illegally charging a player. When he then knocked the ball away from a Kiwi player to prevent a quick throw-in, he saw red.

Yet, surprisingly, the Wallabies then played their best rugby of the game. Stung into action, they added tries by Adam Ashley-Cooper and Rocky Elsom to Mitchell's seventh-minute effort, from a charged-down kick by Dan Carter.

Yet, the contest was over well before half-time because New Zealand were quicker and cleverer at the breakdown and more incisive in their running. They understand that this 'new' game is decided at the tackle, the breakdown, and they played rugby of irresistible power and authority in that phase.

It set up first-half tries for Carter, after he had charged down Berrick Barnes' clearance kick, Mils Muliaina (who later added a second), Richie McCaw, from a ghastly Wallaby error, and Corey Jane. Joe Rokocoko and Corey Flynn added further tries in the final quarter.

In front of a 51,000 crowd at Melbourne's Etihad Stadium, it was New Zealand's second-highest points tally against Australia in their history. You had to go back to 1936 for the last time they scored so many tries. "We are very pleased with the way the guys played," Henry added. "To score seven tries against Australia in Australia is a great performance."